1. Field of the Invention
The present invention relates to a braking system suitable for a two-wheeled motor vehicle having front and rear wheel brakes, particularly a two-wheeled motor vehicle which satisfies racing specifications.
2. Description of Background Art
In Japanese Patent Laid Open No. 196068/95 a braking system for a two-weeled motor vehicle is disclosed wherein hydraulic brakes are disposed respectively for front and rear wheels. A lever hydraulic system for the supply of a hydraulic pressure by operation of a lever is connected to the front wheel brake, while to the rear wheel brake is connected an interlocked hydraulic system provided with a submaster cylinder which produces a hydraulic pressure in interlock with said operation of the lever. A pedal hydraulic system is also connected for the supply of a hydraulic pressure by operation of a pedal.
The submaster cylinder in the above interlocked hydraulic system produces a hydraulic pressure responsive to a change in hydraulic pressure detected by a hydraulic pressure sensor provided in the lever hydraulic system and is supplied with a hydraulic pressure also from the pedal hydraulic system, while the pedal hydraulic system supplies a hydraulic pressure directly to the rear wheel brake and also to the submaster cylinder.
In the above conventional braking system, since the pedal hydraulic system is branched and piped to both the rear brake and submaster cylinders in the interlocked hydraulic system, the number of steps in the piping work and the weight are increased. In addition, a limitation is placed on the piping layout.
Besides, even for the maintenance of either the pedal hydraulic system or the interlocked hydraulic system, the piping must be cut at the joint portion of the two. Maintenance of only one system does not suffice and hence it is impossible to effect a quick unit change for each system. Thus, there is still room for improvement with regard to the maintenance. The request for this improvement has been strong particularly in two-wheeled motor vehicles meeting racing specifications for which a very short time for maintenance is important.
Further, the hydraulic pressure from the pedal hydraulic system is supplied not only directly to the rear wheel brake but also to the submaster cylinder, so in the case of generating a hydraulic pressure also in the interlocked hydraulic system by using the front and rear wheel brakes at a time, there sometimes occurs the case where the hydraulic pressure supplied directly from the pedal hydraulic system and the hydraulic pressure supplied from the interlocked hydraulic system interfere with each other. For avoiding this inconvenience, both structure and control are markedly complicated.